This patent application relates generally to pluggable transceivers for transmitting and receiving signals between electronic devices, such as servers and routers.
Pluggable transceivers are often used in telecommunications and data communications to enable signals to be transmitted between electronic devices. One end of a transceiver may have a mating interface designed to mate to a connector inside an electronic device. The other end of the transceiver may be attached to a cable, which may be routed to another electronic device. For example, pluggable transceivers can be used to connect network devices, such as switches, routers or media converters, via fiber optic or copper networking cables.
Pluggable transceivers include a module connected to a cable and hardware for processing signals disposed inside the module. When used with an optical cable, the cable typically includes one or more optical fibers, such as single-mode or multi-mode fibers. The hardware disposed in the module includes circuitry for converting signals from the electrical domain to the optical domain, for example using lasers, and for converting signals from the optical domain to the electrical domain, for example using photodetectors. When used in electrical communications, the cable typically includes copper wires, and the hardware includes circuitry for modulating and demodulating the signals. In some circumstances, the hardware may further include analog-to-digital converters and digital-to-analog converter. However, in some instances the hardware inside the module may simply provide a connection between the mating interface and the cable so that connections can be made between the electronic device and the cable. Such purely passive components may nonetheless be referred to as a “transceiver” as they support communication between electronic devices in the same way as an optical transceiver or active electrical components, but possibly at lower data rates or over shorter distances.
The mating interface of the pluggable transceiver is plugged into a connector, which is usually mounted on a printed circuit board. The connector may be surrounded by a cage. The cage may be grounded to the printed circuit board, providing electromagnetic shielding around the connector. The cage may have a cavity into which the pluggable module may be inserted to align the pluggable module with the connector. Additionally, the cage may have latching features that cooperate with complimentary latching features on the pluggable module to hold the pluggable module in the cage and in engagement with the connector. To support multiple connections to the same electronic devices, cages may be formed in a ganged configuration, with multiple cavities, each housing a connector for a pluggable transceiver, formed as a unit. In a ganged configuration, a single metal sheet, for example, may form a wall of two adjacent cavities.
Various standards exist that specify form-factors and required performance metrics with which manufacturers of pluggable transceivers must comply. Examples of industry standards include small form-factor pluggable (SFP) transceivers, quad small form-factor pluggable (QSFP) transceivers, and C form-factor pluggable (CFP) transceivers.